AB0813 MULTICENTER ASSESSMENT OF ACRO-OSTEOLYSIS IN PORTUGUESE PATIENTS WITH SYSTEMIC SCLEROSIS
Authors: B. Samões, D. Fonseca, T. Beirão, F. Campos Costa, R. Vieira, G. Terroso, R. Ferreira, R. Nicolau, A. Saraiva, M. J. Salvador, A. C. Duarte, A. Cordeiro, J. P. Vilas, I. Genrinho, A. D. Vieira Bento Silva, L. Gago, C. Resende, P. Martins, N. Madeira, S. P. Dinis, M. Couto, I. Santos, F. Araújo, A. F. Mourão, M. Guerra, M. Oliveira, A. Daniel, M. Rodrigues, C. Dantas Soares, H. Parente, A. Furtado, T. Fontes, A. Aleixo
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Acro-osteolysis is a disabling manifestation of Systemic Sclerosis (SSc). Few is known about its prevalence and clinical associations. <h3>Objectives</h3> To define the prevalence of acro-osteolysis among Portuguese SSc patients, to determine the most sensitive radiological location for its diagnosis and to clarify the phenotype of SSc patients with acro-osteolysis. <h3>Methods</h3> A cross-sectional multicenter study was conducted evaluating SSc patients from 14 Portuguese centers, registered in the Rheumatic Diseases Portuguese Registry (Reuma.pt), that fulfilled Leroy/Medsger 2001 or ACR/EULAR classification criteria for SSc. The presence of acro-osteolysis was assessed through systematic plain radiographs of hands and feet. Statistical analysis with independent parametric or non-parametric tests, multivariate logistic regression of the significant variables in univariate analysis and sensitivity calculation of each radiographed site for the diagnosis of acro-osteolysis were performed. <h3>Results</h3> We included 195 patients, of whom 167 (85.6%) were female, with a median [min, max] age of 64 [20, 90] years-old and a median [min, max] disease duration of 11.2 [2, 57] years. Regarding disease classification, 146 (75.3%) patients had limited SSc, 32 (16.5%) had diffuse SSc, 9 (4.6%) had <i>sine scleroderma</i> SSc and 7 (3.6%) had early SSc. Acro-osteolysis was present in 62 (31.8 %) patients, with the hands (n=49, 25.1%) being more frequently affected than the feet (n=22, 11.3%). The most sensitive location to detect acro-osteolysis was the hand (79.0%). The presence of overall acro-osteolysis was significantly associated with digital ulcers (p=0.001), flexion contractures (p=0.031), oesophageal (p=0.006), gastric (p=0.014) and lung (p=0.004) involvements, higher mRSS score (p&lt;0.001), anti-topoisomerase I positivity (p=0.034) and radiological calcinosis (p=0.018). Patients with hand acro-osteolysis had longer disease duration (p=0.02) and were more often affected by digital ulcers (p=0.004), flexion contractures (p=0.041), oesophageal (p=0.001), gastric (p=0.015) and lung (p=0.001) involvements, higher mRSS score (p&lt;0.001), anti-topoisomerase I positivity (p=0.004) and radiological calcinosis (p=0.008). No significant differences were found between patients with and without feet acro-osteolysis. In multivariate analysis, anti-topoisomerase I positivity (OR 4.6, 95%CI 1.3-16.4, p=0.017) was predictor of hand acro-osteolysis. <h3>Conclusion</h3> The prevalence of acro-osteolysis found in Portuguese SSc patients is within the range found in the literature (20-40%) <sup>[1]</sup>. The hands were the most sensitive location to detect acro-osteolysis – a novel aspect since, to our knowledge, this is the first study evaluating acro-osteolysis in the feet besides the hands. Our data replicated some previously reported associations between acro-osteolysis and other hand involvements (digital ulcers, calcinosis and flexion contractures) and systemic complications (esophagogastric and pulmonary systems) <sup>[2-4]</sup>. Anti-topoisomerase I positivity appears to increase the risk for hand acro-osteolysis. <h3>References</h3> [1]Sandler RD et al. Musculoskeletal hand involvement in systemic sclerosis. Semin Arthritis Rheum. 2020 Apr;50(2):329-334. [2]Sakchaikul et al. Prevalence and clinical association with acro-osteolysis in early systemic sclerosis. Clin Exp Rheumatol. 2021 Sep-Oct;39(5):1093-1098 [3]Sakata et al. Association of radiographic findings in hand X-ray with clinical features and autoantibodies in patients with systemic sclerosis. Clin Rheumatol. 2020 Jan;39(1):113-118 [4]Johnstone et al. Acro-osteolysis in systemic sclerosis is associated with digital ischaemia and severe calcinosis. Rheumatology 2012;51:22342238 <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.